兔VX2肝癌TACE前后MRDWI与病理对照研究

The Correlation between MR Perfusion Imaging and Pathology in Rabbit VX2 Liver Cancer before and after TACE

目的:本研究利用兔VX2肝癌模型,探讨肝癌化疗栓塞后MR弥散加权成像及病理表现,为肝癌化疗栓塞后的疗效评价提供理论基础。方法:新西兰大白兔15只,制成VX2肿瘤模型。随机分为3组,分别为TACE术前、术后三天、术后一周组。种植3周,进行肝动脉化疗栓塞。采用sendinger穿刺技术,将3F微导管超选入肿瘤供血动脉,注射碘油、MMC(1mg)及表阿霉素(1mg)混合物0.5～lmL,至碘油沉积良好、肿瘤血管消失停止。各组在TACE术前、术后三天、术后一周分别进行MR弥散加权成像。DWI采用单次激发平面回波成像序列,弥散因子b值取0s/mm^2和300s/mm^2,TR 6000ms,TE 49ms,FOV 150mm,层厚3mm,层间距0mm,矩阵112×112,重建矩阵256×256,翻转角90°,扫描时间2分36秒,NSA为6次.成像之后动物处死,切取肝脏肿瘤组织块,进行HE染色、病理观察。结果:化疗栓塞前,MR DWI可见高信号肿瘤灶。光镜下肿瘤组织细胞体积增大,胞浆丰富,淡红染色,核肥大,核分裂像多见,可见少量坏死,周边区和中央区未见明显区别。栓塞后3天,肝左叶肿瘤DWI上为高信号区,出现斑片状低信号区。光镜下出现大量核碎裂、核溶解,肿瘤坏死较多。栓塞后1周,在DWI上低信号的坏死区增加。光镜下核碎裂、核溶解、肿瘤坏死增多。结论:MR弥散加权成像与病理表现一致,较好地体现了肝癌化疗栓塞后的转归。

Objective： To study the correlation between MR perfusion imaging and pathology after transcatheter arterial chemoembolization （TACE） using VX2 liver cancer model and to provide a theoretical basis to evaluate the curative effect of TACE. Methods： Fifteen New Zealand white rabbits （weight： 2.5-3.0kg） were randomly divided into three groups, with 5 in each group （group 1, pre-TACE; group2, 3 days after TACE; group 3, 1 week after TACE）. The rabbit VX2 hepatic carcinoma models were presented in all rabbits. All of the three groups received TACE at three weeks after the tumor was implanted. The MR perfusion imaging was performed before chemoembolization, at 3 days and 1 week after chemoembolization respectively for group 1, 2 and 3. Each animal was then sacrificed for pathology observation after MR examination. Results： The lesions assessed before TACE were hyperintense compared with the surrounding liver parenchyma on DWI images. The volume of neoplastic cells became large. Nucleus was hypertrophic with different size and shape. Phase of nucleous mitosis showed in many cells and necrosis was hardly seen. No obvious difference was found between the peripheral area and the core area. At 3 days after TACE, the heterogeneous hypo-intense was observed on DWI images. Many nuclear fragmentation and caryolysis appeared on pathology. Neoplasm necrosis was seen. At 1 week after TACE, the heterogeneous hypo-intense areas became larger. Light microscopy showed incomplete necrosis. There were increased karyopycnosis and nuclear fragmentation. Conclusion： MR perfusion imaging of VX2 liver cancer corresponds well with pathology and can reflect the outcome of liver cancer after TACE.